Air filter



FIG. 1 shows a front view of an air filter showing my new design;

FIG. 2 shows a rear view thereof;

FIG. 3 shows a right side view thereof;

FIG. 4 shows a left side view thereof;

FIG. 5 shows a top view thereof;

FIG. 6 shows a bottom view thereof;

FIG. 7 shows a top, front and left side perspective view thereof;

FIG. 8 shows a bottom, back and right side perspective view thereof;and,

FIG. 9 shows a partial cross-sectional view thereof, taken along line9-9 in FIG. 3.

The broken lines in FIGS. 3-8 are included for the purpose ofillustrating portions of the air filter that form no part of the claimeddesign.

The ornamental design for an air filter, as shown and described.